Throughout the present description and in the subsequent claims, the expression “assembly of bicycle components in mutual rotation”, is used to indicate any bicycle assembly defined at two bicycle components assembled together so that, during pedalling, they can rotate with respect to one another. Such an assembly therefore comprises at least one support element, at least one rotary element supported in rotation by the support element and at least one member arranged between the support element and the rotary element to allow the relative rotation of one element with respect to the other element. Examples of such an assembly are a bottom bracket assembly, a hub assembly or a steering assembly.
The invention also relates to a bicycle comprising the aforementioned assembly. Preferably, such a bicycle is a racing bicycle.
In the field of bicycles, above all in racing bicycles, the problem of the smoothness capability of those components that, during pedalling, are in mutual rotation has always been researched. This has been done as part of the continuing search to improve the bicycle performance.
Typically, the rotation of one component with respect to another in bottom bracket assemblies, or in hubs or in steering tubes, of bicycles is achieved through the use of rolling bearings.
In the past it has been observed that the initial smoothness capability of bicycle components assembled together and in relative rotation decreased over time, until it substantially reduces after a certain time; this phenomenon was due essentially to the accumulation on the bearings of atmospheric and/or polluting agents.
In order to limit this phenomenon, in racing bicycles nowadays ball bearings are used to which insulating grease is applied; indeed, the grease hinders the formation of corrosion. In order to hold the grease and therefore protect the inside of the bearings from the undesired action of atmospheric and/or polluting agents, special protective screens are used.
Despite the aforementioned provisions, a decrease in the time of smoothness capability of the bicycle components is still observed.
The technical problem at the basis of the present invention is therefore to ensure, in the assemblies of bicycle components in mutual rotation, a high smoothness capability for an extended time period.
The present invention therefore relates, in a first aspect thereof, to an assembly of bicycle components in mutual rotation, comprising a support element, a rotary element rotatably coupled with the support element, at least one bearing arranged between the support element and the rotary element, said at least one bearing comprising a first bearing element firmly coupled with one element from said support element and said rotary element, characterised in that said first bearing element and said one element from said support element and said rotary element have, at respective mutually coupled interface surfaces, a standard reduction potential difference lower than or equal to 0.3 V, in absolute value.
Throughout the present description and in the subsequent claims, the expression “firmly coupled”, is used to indicate a coupling without relative motion between the two coupled elements.
Throughout the present description and in the subsequent claims, the expression “bearing” is used to indicate any member intended to be arranged between a first bicycle element and a second bicycle element to allow the relative rotation of one element with respect to the other element. Such a member can have the classic configuration of a rolling bearing, with two rings and a plurality of rolling elements arranged between the two rings, or a similar configuration, in which for example one of the rings is omitted and the race for the rolling elements is defined directly on one of the two bicycle elements in mutual rotation.
Throughout the present description and in the subsequent claims, the expression “standard reduction potential value”, is used to indicate the value of the electrode potential referring to the standard hydrogen electrode and measured at the following standard conditions: temperature 298 K, pressure 1 atm, concentration of the participants in the reaction of 1 M.